1) Field of the Invention
The invention herein relates to manufacturing equipment, specifically an improved cutting fixture for heat-shrink film sleeve labeling machines.
2) Description of the Prior Art
The operating approach of conventional sleeve labeling machines involves pulling heat-shrink film past a center guide post such that after the heat-shrink film is drawn into a tubular state, it is cut to the required length, slipped over a container such as a bottle, and then heated to fix the already cut heat-shrink film onto the container.
The arrangement of the cutting fixture in such conventional heat-shrink film sleeve labeling machines, as shown in FIG. 1, typically consists of revolving blade mounts 2 each carrying a blade 3 and disposed at equal intervals apart in a circular star pattern surrounding the center guide post 1, a circular groove 4 around the center guide post 1 facing towards the blades 3, a gear (not shown in the drawings) situated on the revolving blade mount 2, and a motor 5 driving two cogged belts 6 and 7 that are coupled to the revolving blade mount 2 via a transmissive wheel which enables the simultaneous rotation of all the revolving blade mounts 2, while causing the blades 3 to rotate within the circular groove 4 of the revolving blade mount 2 and thereby cut the heat-shrink film sleeving. Since the cogged belt 7 drives all of the said revolving blade mounts 2 to rotate simultaneously such that a synchronized 360-degree rotation occurs prior to each instance of cutting by the blades 3. Although such an operating approach achieves the objective of cutting the heat-shrink film sleeving, the following shortcomings happen:
1. Since the said revolving blade mount 2 and blade 3 must rotationally travel 360 degrees to perform a cut, a minimum of 180 degrees or more of travel and time are wasted because no work is done, a shortcoming which obviously hampers cutting rate and makes it impossible to increase production efficiency.
2. Since the cogged belt 7 of the said revolving blade mount 2 is a looped construct, long-term usage gives rise to elastic fatigue and results in elongation from stretching such that after a period of cutting operation, the revolving blade mount 2 and blades 3 are no longer capable of synchronized rotational cutting and fully cutting the heat-shrink film sleeving, leaving partially cut areas or slashes that impart unevenness. Although Idler wheel 8 constantly exerts pressure against the cogged belt 7 and remedies the said drawback, this is still a troublesome and inconvenient operating fault.
3. Since the blades 3 must be replaced regularly to maintain edge sharpness and smoothness, and the said revolving blade mounts 2 have to be kept capable of 360-degree free rotation, during blade 3 replacement, the operator must grasp or exert force against the cogged belts 6 and 7 with one hand and then remove and install the blade screws 9 with the other hand, a procedure that is obviously troublesome, inconvenient, and hazardous, while also adversely affecting the usable service life of the cogged belts 6 and 7.
To improve upon the said shortcomings, manufacturers have introduced another type of cutting fixture, as indicated in FIG. 2, FIG. 3, and FIG. 4, consisting of a plurality of blade assemblies 20 pivotably disposed on an upper and a lower mounting frame 11 and 12 surrounding the outer periphery of the center guide post 1; a shaft 201 in each blade assembly 20, the bottom extremity of which is fitted though an identical bearing 202 and into a connecting socket 203; a dial plate 204, a mounting base 205, a blade adjustment base 206, a blade 207, and a clamp plate 208 respectively positioned under the bottom portion of the connecting socket 203; and an eccentric shaft 209 at the top extremity of each shaft 201 that is pivotably disposed facing the hole area of a drive plate 200; additionally, a belt wheel N is installed on the shaft 201 of one blade assembly 20 that enables 360-degree driven rotation via a cogged belt P connected to an external power structure (such as a motor), the resultant coordinated operation of the eccentric shaft 209 and the drive plate 200 causing all the blades 207 to synchronously rotate 360 degrees while projecting and retracting (as shown in FIG. 4). Such an operating approach is undeniably workable as there is a solution for the drawback of the prior art revolving blade mount 2 and blade 3 due to the elastic fatigue of the cogged belt 7 that results in a loss of synchronized cutting performance; however, what has not been improved is the shortcoming wherein the said minimum of 180 degrees of travel and time are wasted and no work is done because the said blades 207 must rotate 360 degrees to complete a single instance of projection and retraction for the cutting operation; at the same time, since the said blades 207 all freely rotate 360 degrees, replacing the blades 207 as previously stated is a troublesome, inconvenient, and unsafe procedure and, furthermore, the service life of the cogged belt P is shortened; additionally, since the bearing 202 is situated at the top end of the said connecting socket 203 and the dial plate 204, the mounting base 205, the blade adjustment base 206, the blade 207, and the clamp plate 208 are at its lower end, the overall weight is so excessive that when driven at a high rate of rotation, stability is compromised, resulting in slashes that impart an uneven quality and poor appearance in the heat-shrink film.
To further enhance the practicality and performance of the cutting fixture of the said heat-shrink film sleeve labeling machine, manufacturers introduced the cutting fixture shown in FIG. 5 and FIG. 6, which consists of a plurality of blade assemblies disposed in circular pattern at equal intervals apart on a mounting frame 11; a separate, vertical first and second shaft 30 and 50 along which the said blade assemblies traverse; and an eccentric rod 32 of a different angle at the bottom extremity of the first shaft 30 in the hole of a drive plate 40, wherein the blade assembly first shaft 30 has a drive wheel 35 that enables 360-degree driven rotation via a cogged belt P connected to an external power structure (such as a motor), causing all the first shafts 30 to synchronously rotate in the same direction.
The said first and second shaft 30 and 50 have an upper eccentric rod 31 and 51 at their respective distal extremities and, furthermore, each group of two upper eccentric rods 31 and 51 is linked by a connecting rod 60 such that the first shaft 30, via the upper eccentric rod 31 and 51 as well as the connecting rod 60, cause each second shaft 50 and blade 70 at the bottom end to swing to the left and right, alternately projecting and retracting for the cutting operation.
Such an operating approach is arguably better than the preceding prior art; since the blade cutting action consists of a left and right reciprocation, not the said 360-degree rotation, that results in less idle time and travel, the arrangement provides for higher efficiency; however, the aspect of inadequacy is that achieving the projecting and retracting cutting action of the blade assemblies on the said drive plate 40 requires the installation of the connecting rod 60 between the first shaft 30 and the second shaft 50 of each blade assembly as well as other components (such as bearings and bearing seats, etc); as such, the structure is obviously of greater complexity and, furthermore, fabrication and assembly as well as maintenance and repair are more difficult, inconvenient, and uneconomical; additionally, since the projecting and retracting cutting action of the blades is based on the coordinated articulation of the connecting rod 60 along with the upper eccentric rod 31 and 51 of the first and second shaft 30 and 50, an unobstructed free swinging capability is maintained at all times; as such, during blade replacement, the operator must grasp the cogged belt P with one hand to keep the first shaft 30 and the drive plate 40 stationary and use the other hand for removing and installing the blade, a procedure which still has the drawbacks of being troublesome, inconvenient, and hazardous.
As conveyed above, the heat-shrink film cutting fixtures of conventional sleeve labeling machines still have shortcomings that require improvement.
The primary objective of the invention herein is to provide an improved cutting fixture for heat-shrink film sleeve labeling machines in which a plurality of blade assemblies are disposed at equal intervallic degrees apart in a circular pattern around the outer periphery of the center guide post, with each having their eccentric shafts situated at drive plates to maintain synchronized operation, and a power structure directly driving the eccentric shafts of the blade assemblies into reciprocal rotation at a settable angle, thereby maintaining the synchronization of the blade assembly blades and enabling a reciprocally rotational cutting action in a simple arrangement that increases production efficiency.
Another objective of the invention herein is to provide an improved cutting fixture for heat-shrink film sleeve labeling machines in which the shaft of each blade assembly blade is limited by a check plate and anchoring screws during reciprocal rotation so that 360-degree free rotation cannot occur so that the removal and installation of the said blade is not only simple, convenient, and rapid, but safer and of higher efficiency.
Yet another objective of the invention herein is to provide an improved cutting fixture for heat-shrink film sleeve labeling machines in which the power structure provides for setting the angle of reciprocal rotation, including the cogged belt, the transmission components, and so on are which are in a state of partial contact such that when wear occurs at points of contact, adjustment and changes can be effected at those positions, which not only enables precise and positive power transmission, but at the same time provides for prolonged service life and economic value.